A set implies hitting three of a kind while holding a pocket pair. For example, you have a set if you are dealt 33 and the flop is K 9 3 rainbow while you have three of a kind when you are dealt A3 and the flop is 3 3 K rainbow, there is no difference between a set and three of a kind in hand strength, only how you made the hand.

A player with fewer relative blinds in their stack. usually used to refer to players with stacks of 20bb or lower

A bluff with a hand that has the potential to become a made hand should the bluff itself prove to be ineffective.